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ms; BENJAMIN.

ELECTRIC LAMP SOCKET. APPLICATION FILED JAN-29, 1915.

1,33 07, Patented Apr. 13, 1920..

4 SHEETS-SHEET I- g6 mam! f -ll llllilmi'ii 4 .Jlllllllli 32 mum :I/ AXE 4m? W R. B. BENJAMIN.

ELECTRIC LAMP SOCKET.

APPLICATION FILED 5AN-29,.19I5.

L336,607, Patented Apr. 13, 1920.

4 SHEETSSHEET 2.

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WZWZZW R. B. BENJAMIN.

ELECTRIC LAMP SOCKET.

APPLICATION FILED SAN. 29. 1915.

1,336,607. Patented Apr. 13, 1920.,

4 SHEETS-SHEET 3.

R. B. BENJAMIN.

ELECTRIC LAMP SOCKET.

APPLICATION FILED JA-N.29, 1915.

1,336,607. Patented Apr. 13,1920. 4 SHEET -SHEET 4.

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UNITED $TATES PATENT QFEICE.

REUBEN B. BENJAMIN, 0E CHICAGO, ILLINOIS, ASSIGNGB, TO BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLI- nors.

ELECTRIC-LAMP SOCKET.

asacov.

T 0 all whom it may concern:

Be it known that l, REUBEN B. BENJAMIN, a citizen of the United States, residing at Chicago in the county of Cook and State of Illinois, have invented new and useful improvements in Electrioliamp Sockets of which the following is a full, clear, concise and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to electric lamp sock ets. and specifically to sockets for use in connection with a. feed circuit comprising an inner insulated conductor and an outer bare grounded conductor.

Among the objects '01" my invention are to provide a socket which shall be simple in construction, easy to manufacture and ethcient in use and operation.

Further objects will appear from the detailed description to follow and from the appended claims.

in the drawings, in which I have illustrated several embodiments of my inven tion Figure 1 is a sectional view illustrating my invention.

Fig. 2 is a section on the line 22 of Fig. 1.

Fig. 3 is a section on the line 33 of Fig. 2 showing the manner in which the binding post screw is secured to the center contact;

Fig. 1 is a perspective view of the center contact; a

Fig. 5 is an axial section of a modification of my invention;

Fig. 6 is a section on the line 6-6 of Fig. 5;

Fig. 7 is a plan view of the socket removed from the feed circuit, showin the split sleeve at the upper end of the socket;

Fig. 8 is a perspective view oi? the center contact shown in Figs. 5 and 6;

Fig. 9 shows an axial section of another term of socket embodying; my invention.

Fig. 10 is a section on the line 10-10 of 9 showing the threaded contact shell cut away opposite the binding screw for the center contact; j v

Fig. 11 is a perspective view of the insulating base showning the ti-shaped projection forming a backing for the center contact;

Fig. 12 is an axial section of a lamp socket showing another term of my invention;

Specification of Letters Patent.

Patented Apr. 13; 1920.

Serial No. 5,055.

'. 13 is a section on the line 1313 of contact; and

17 is a perspective view of a modification of the center contact in which the contact member is not provided with a slot.

Referring now to the drawings in detail. and first to the modification of Figs. 1 to 1 inclusive the teed or supply circuit com: prises an inner insulated conductor 9, an outer bare grounded conductor comprising a pipe 10 loosely surrounding the conductor 9 and having a. threaded end 11 for engagement with an internally threaded bushing or sleeve 12 of a socket whichbushing is secured to the casing 13 which surrounds the insulating base 1 1 which supports the center contact of the lamp socket. The bushing 12 is held in properly adjusted position on the pipe 10 by means of a set screw 15 threaded in an opening in the bushing and engaging the end of the pipe 10. The bushing 12 is provided at its lower end with a hollow split rivet portion 16 for engagement with a correspondingly shaped split portion 17 ot the casing 13, alternate sections 18 and 19 of the split portions being bent over farther than the. adjacent sections to prevent relative rotation between the cats ing and bushing. The casing 13 adjacent the split portion 17 is bent so as to partially surround a reinforcing washer 21 which not only re-inforces the casing but serves as a backing to prevent injury to the casing when the rivet portions 18 and 19 are split and bent down. The casing comprises a cylindrical portion 22 surrounding the insulating base 14: and a threaded shell. contact 23 for enga gemcnt with the threaded contact of the lamp base,v which threaded portion 23 may also form a support for a shade holding device 24 as shown in Fig. 1. The casing 1-3 is headed outwardly as shown at 25. above tee threaded portion 23 to-limit the distance to which the shade holding device 241 can be screwed onto the socket. After the insulating base 1 1 is slipped in place in the casing 13 the casing is beaded inwardly, as shown at 26, to hold the base 14 firmly and permanently ithin the cas- 'cuit, threaded. contacting. The insulating base lei is provided with a recess 27 in. its uppe lace-to accommodate the split portions 16 and 17 of. the bushing and casing. The base 14s is also provided with a small recess 28 on its upper face into which a portion of the casing 13 forced, as shown at 29, to prevent relative rotation between the casing and base. A center recess 30 is also provided in the base 14; to accon'unodate the insulation surrounding the inner conducton A central passage 31 leads from the recess 80 to permit the passage of the wire from the inner conductor. A center contact 32 of the socket comprises a U-shaped spring contact portion 33 which offset from the base portion 34: to permit the wire from the inner conductor to he led out sidewise from the central opening 31. The base portion 34f has an opening 35 through which extends a bolt 2-36 provided with a nut 37 non-rotatably seated in a recess 38 in the upper face ot the base 1% whereby the center contact is secured to the base. The base 14 is provided with a U-shaped projection 35 forming a backing for the U-shaped contact portion 3-3. A binding screw elO extenos through an opening all in the base 34 and provided with a nut 12 non-rotatably held in a recess 4-3 in the lower face of the base 14;. The wire aid from the inner conductor 9 is led hrough the opening l5 in the U-shaped center contact 33 and is wound around the binding screw 4-0 as shown in 2 and The circuit from the insulated conductor 9 through the socket and lamp to the grounded conductor 10 is through the wire 44., base 3%, center contact 83, lainp cir- 23, casing 22 and bushing 12 to the pipe 10-, it bet noted thatthe bushing 12 not only s to ruechanically connec the socket 1 the pipe 10 and support it thereon, but also serves as part of the electrical. connection between the threaded contact of die lamp base and the grounded outer conifluctor 10.

In the. modification of Figs. 5 to 8. the feed circuit comprises an inner insulated conductor 46 and an outer grounded conductor comprising a coil oi. wire 4' wound around the inner conductor and forming a sheath or armor for the inner comluctor as well as a ground return. The socket coinprises a casing 48 for the insulating base 49, the upper portion of the casing 4&8 being provided with a tapering threaded neck or sleeve portion 50 which is split, as shown at 51, to permit its being clamped tightly on the outer conductor to hold it firmly in place and to secure a good electrical. connection. A tapered nut 52 may be screwed down on the sleeve portion 50 after the latter is screwed or slipped in place on the outer conductor 47, the nut 52 forcing the split portions of the sleeve 50 into firm contact with the conductor it as it is screwed down. A set screw 53 is threaded through the nut into engagement with the sleeve 50 to hold the nut 52 in adjusted position. The casing d8 also comprises a threaded shell contact 54: for engagement with the threaded contact of the lamp. After the insulating base l9 is slipped into the casing 18 the casing is beaded inwardly as shown at 55 to hold the lease in the easing. A bead 56 is also provided above the threaded portion 5 to limit the distance to which the shade holding device may be screwed onto the socket. The upper face of the insulating base 4-9 is providedwitha small recess 58 into which portion of the casing 48 is forced to prevent relative rotation between the casing and base. The base 49 also has a central recess 60 in its upper face to accommodate the insulation on the inner conductor 16. An opening 61 extends from the recess 60 through the base 49 through which the wire from the conductor 46 extends. lhe center contact of the socket 62 comprises a U-shaped contact portion (33 which is off-set from the base portion 74- to permit the wiring from the conductor 46 to be led out sidewise from the opening 61. The base 74 comprises a tongue portion 75 having an opening 76 through which extends a hollow rivet 77 which also extends through the opening 61 and is riveted over at its ends to hold. the center contact 62 firmly on the base 49. A binding screw 78 extends through an opening 79 in the base 74: and is provided with a nut 80 which is non-rotatably held in a recess 81 in the lower face of the base 49. The base- T l is provided with a struck up portion 82' to hold the end of the wire from the conductor l6 in place after it is wound around the binding screw '2' 8. The insulating base 4-9 is provided with a projection. 83 which serves as a backing for the U-shaped spring contact 63.

The circuit in this modification from the inner conductor 46 to the outer grounded conductor 17 is through the center contact 62, lamp circuit, threaded contact 5%, casing 4.8 and sleeve 50 to the grounded conductor I7. I

In the modification of Figs. 9, 10 and 11 the feed circuit is the same as in the inedification of Figs. 5 to 8 and the insulating base and center contact and connections are also the same.

I have shown. however, a modified form of the means for holding' the insulating base 49 in placein the casing 84:. The casing 84 is provided with a head with which engages a head 85 formed on the threaded (ontact 86, the bead 85 being formed after "the 19 and threaded contact 86 have been slipped into place in the casing 8d, the upper edge 87 of the contact 86 engaging the lower face of the base 49 to hold the latter firmly in position in the casing. The threaded contact 86 is cut away as shown at 88 in Figs. 9 and 10 to prevent short circuiting between the connections with the center contact 62 and the threaded contact 86. The lower portion of the casing'84l may be provided with a bead 89 for use in con necting a shade holding device.

In this modification the circuit from the inner conductor 4L6 to the outer grounded conductor t? is through the center contact 62, lamp circuit, threaded contact 88, casing 84 and sleeve 50 to the grounded conductor etT. In wiring all of the modifications of sockets so far described the socket is brought into position with respect to the feed circuit with the wire from the inner insulating conductor 9 extending through the central opening in the'insulating base after which the socket is rotated to thread the bushing onto the threaded end of the outer grounded contact. the fact that the opening through the insulating base through which the wire from the inner conductor extends is central of the insulating base permitting this rotation of the socket without distorting the wire. It will be noted, too, that in all of the modifications so far described the center contact is provided with an opening through which the wire from the inner conductor .ia r extend whereby the wire from the inner conductor may be easily thread-ed through the opening in the insulating base and the opening in the center contact. After the socket is screwed into position on the outer conductor the wire trom the inner conductor is bent over and wound around the binding post to secure it in engagement with the center contact.

In Figs. 1217 I have shown a still further modification of socket in which the feed circuit includes a center insulated conductor 90 and an outer thin sheath of metal forming a ground return. In this modification the socket instead of being screwed onto the outer conductor, is slipped over the neck of a supporting base and the necks of both the socket and base are clamped onto the outer conductor by means of a clamping ring.

In this modification I have also shown a form of center contact in which the usual minding screw is dispensed with. T he supporting base 92 comprises a flat plate 93 having a number of openings 94 through which screws may be inserted for securing the base in position, and a sleeve or neck portion 95 which is split as shown at 96 13) to permit of its being clamped tightly on the outer conductor 91. The socket casing 9'? comprises a neck or sleeve portion 98 engaging and surrounding the neck portion 96 and is split as shown at 99 (Fig. 13) to permit of its being clamped tightly on the neck 95. A clamping band 100 surrounds the neck 98 and is provided with ears 100 through which extends a clamping bolt 101 for drawing the ears together to clamp the socket and base firmly on the outer conductor 91 to afford a good electrical connection therewith. The upper end of the neck 98 is flanged over slightly to engage the upper edge of the clamping band 100 to prevent the socket from slipping'out of the clamping band. I he socket comprises a threaded shell contact 103 for engagement with the shell contact of a lamp base, a bead 10% being provided above this threaded portion for engagement with the upper edge of a shade holding device. A head 1.05 is also provided to hold the insulating base 49 in position. i

The upper face of the insulating base 49 provided with a central recess 106 to accommodate the insulation on the inner conductor 90. A rectangular opening 107 leads from the recess 106 through the insulating base 4-9to provide passage for the wire from the inner conductor and also to permit of the connection of the center contact. A pair of inclined shoulders 108 are provided on opposite sides of the upper end of the passage 10'? for holding the center contact in place. The center contact comprises a middle contact portion 109. substantiallv circular, having a slot 110 through which the wire from the inner conductor 90 is threaded when the socket is being placed in position. Extending from opposite sides of the middle contact portion 109 is a pair oi arms 111 provided at their upper ends with outwardly inclined portions 112 for engagement with the inclined shoulders 108. The length of the arms 111 is such that when the center contact is slipped into position. in the opening 107 a space will be left between the lower part of these arms and the insulating base 49 to permit the end 113 of the wire from the inner conductor 90 to be bent over and wound around the arms 111. As heretofore described, the opening 107 is rectangular in cross section so that the center contact 109 will be prevented from twisting around in the opening as the wire 113 is wrapped around it.

In Fig. 17 I have shown a modified form of center contact havn'r a middle contact portion 114: substantially circular which is not provided with an opening. From opposite sides of this middle portion 114:. arms 115 extend upwardly and terminate in onpositely inclined portions 116 for engagement with the shoulders 108. Whenthis Form oi center contact is used the wire 118 i s threaded through the insulating base and bent over to one side before the center contact is placed in position. After the center contact is placed in position the end 118 is wrapped around the center contact as in the modification of Figs. 12, 14- and 16. In

this modification the circuit from the insulated conductor 90 to the grounded conductor 91 is through the wire 113, center contact 109, lamp circuit, threaded contact 103, casing 97 and sleeves 98 and 95 to the grounded conductor 91.

In all of the modifications it will be noted that the casing for the insulating base which supports the center contact forms a part of the return circuit and is electrically connected with the outer grounded conductor and also with the threaded shell contact which engages the shell contact of the lamp base.

It will be noted that in all the modifications the casing of the lamp socket is mechanically and electrically connected with the outer grounded conductor by means of a sleeve surrounding the grounded conductor.

It is obvious that it is not necessary that the outer grounded conductor should surround the inner insulated conductor throughout its length, but that it' may be grounded in any suitable manner.

This application is a continuation, so far as common novel subject-matter claimed herein is concerned, of my Patent No. 1,154,963, dated September 28, 191.5, separable attachment plugs, application for which was copending with this application and was filed November 21, 1908.

Having thus described my invention what I claim as new and desire to secure by Lett-ers Patent is 1. A lamp socket comprising an insulating base having a substantially central opening therethrough for a feed wire, a center contact supported by said insulating base, said center contact comprising a U shaped portion between the arms of which the said wire is to extend andawiring terminal supported by said center contact.

2. A lamp socket comprising an insulating base having a substantially central opening therethrough for a feed wire, a center contact supported by said insulating base, said center contact comprising a U- shaped portion between the arms or which the said wire is to extend, a binding plate portion to which the end of said wire is to be secured and a wiring terminal for securing said wire.

8. A lamp socket comprising an insulating base having an opening theretlirough for a feed wire, a center contact, means for securing said center contact to said base comprising a hollow rivet extending through said opening, said center contact comprising a U-shaped contact portion, a base struck up from said U-shaped portion, said base having an aperture through which said hollow rivet extends and a wiring terminal supported by said struck-up base.

In witness whereof, I have hereunto subscribed my name in the presence of two w1tnesses.

REUBEN B. BENJAMIN. Witnesses:

MARGARET THIELEN, ANN! SOLOMON, 

